It's definitely a different environment. Free MMOs attract... well, not so good people, on account of them being free. So you get a lot of kiddies in there trying to flex their e-peens. The quality of people willing to spend money on a game monthly is generally higher than young 'ens afraid to use their mom's credit card, making them resort to stuff like Runescape.

It's a pretty good game, all-around, if you're looking for an interesting MMO experience.